Background checks for guns: What you need to know

Lawmakers reached a compromise Wednesday to expand background checks to cover buyers at gun shows and shopping on the Internet, just like those already required when buying from licensed dealers. NBC's Kelly O'Donnell reports.

Two critical senators with “A” ratings from the National Rifle Association proposed a deal Wednesday that would expand background checks on firearms sales, which are currently required on purchases from federally licensed dealers. The compromise proposal put forward by Senators Joe Manchin and Pat Toomey would mandate them for sales at gun shows and on the Internet as well, yet make an allowance for transfers between family members.

More than 167 million checks were made through the FBI's system between 1998 and early 2013, but the process remains obscure to many Americans. What are background checks, and why has it taken so long for lawmakers to piece together a deal on a measure polls say is overwhelmingly favored by American voters? Here’s a primer:

The Brady Handgun Violence Prevention Act of 1993 established the National Instant Criminal Background Check System (NICS), which allows the seller to check a buyer’s eligibility with a search that usually takes less than a minute. The system was fully launched in 1998. Before selling a gun, the gun store worker calls in to the FBI or other designated law enforcement agency to run a check against the system’s records. If the prospective buyer’s record doesn’t raise a red flag – possible triggers include a person having been adjudicated as mentally ill or being sought by law enforcement – the sale is cleared to go through.

What kinds of gun purchases don’t require background checks under current law?

That depends on where you live. In the wake of the Newtown school shooting, President Obama asked for a federal law that would require universal background checks, including at gun shows. Right now, only California, Colorado, Illinois, New York, Oregon, and Rhode Island require background checks at gun shows, according to the Coalition to Stop Gun Violence. But most states have looser restrictions. While local laws can vary widely, 33 states do not have a law addressing what is commonly referred to as the “gun show loophole.” Similarly, regulations on sales between private parties or transfers between family members can be very different from state to state, where they exist at all.

Is the background-check system foolproof?

Critics of the current background check system point to gaping holes in the ways states submit records to the NICS. While 44 states have individual laws regulating the sale of firearms to the mentally ill, for example, far fewer states submit the names of prohibited mentally ill individuals to the national database. Just seven states account for 98 percent of the names prohibited for mental illness, according to Mayors Against Illegal Guns, meaning most states are in there barely, if at all. In one oft-cited example, Virginia Tech shooter Seung-Hui Cho passed a background check before obtaining a gun and killing 32 people, despite having been declared mentally ill two years before. States are responsible for compiling mental health records from courts, hospitals, and other sources to submit to NICS, but they are not legally required to do so.

Does the public support broader background checks?

The vast majority of American voters do. Eighty-five percent of Americans said they support background checks at gun shows and for private sales in a Pew Research Center poll released earlier this year. Other polls have found even wider support for broadening checks, with 92 percent of respondents to a February survey by Quinnipiac University saying they favored them on every single gun sale. That number dropped to 91 percent among gun-owning households.

That’s a harder question to answer, as the issue becomes bitterly political. Momentum on Capitol Hill toward a bill requiring comprehensive background checks has been slow to gain traction. Republican Senators Ted Cruz, Rand Paul, and Mike Lee said that they would filibuster debate on new gun legislation, but that idea lost steam on Tuesday as other Republican lawmakers including Sen. John McCain said they would not support a filibuster. The NRA released a statement on Wednesday after the Manchin-Toomey compromise was announced saying that expanding background checks “will not prevent the next shooting, will not solve violent crime and will not keep our kids safe in schools.” Other opponents of expanded background checks have argued that they would require a national registry of gun owners, something the White House has denied.

Are background checks effective?

The numbers show that background checks do keep guns out of the hands of at least some people who are not supposed to have them. Nearly 1.8 million applications for firearm transfers or permits were denied between the passage of the law in March 1994 and December 2008, according to the Bureau of Justice Statistics. The FBI and state law enforcement denied firearm purchases to 153,000 people in 2010 alone, the most recent year for which data is available.

Jim Lo Scalzo / EPA file

Shoppers examine handguns on display for sale at The Nation's Gun Show held in the Dulles Expo Center in Chantilly, Virginia, USA, 28 July 2012.